Conventionally, recording media processing devices are known which are disposed adjacent to the main body of an image forming device such as a copier or a printer and serve, for example, to perform after-processing (such as punch processing, staple processing and other binding processing) on recording media on which an image has been formed. These recording media processing devices perform staple processing (binding operation) and the like on recording media that has been output from the image forming device main body and stacked on a processing tray after passing through a transport path. Thus, when the stack of recording media undergoes staple processing, edge stapling or center stapling is performed by the stapler, but while staple processing is being performed in the processing tray, it is not possible to feed the next stack of recording media into the processing tray, and it is therefore necessary to provide a pause in the transport of the recording media during staple processing. However, this reduces the productivity of the recording media processing device.
Consequently, an after-processing device for image forming devices has been proposed which comprises, as shown in FIG. 6, a shunting roller 100 for receiving recording media during staple processing, transport paths 101a and 101b which are disposed substantially tangential to the shunting roller 100, and a shunting path 102 which is provided around the outer circumference of the shunting roller 100.
With this after-processing device, while a stack of recording media is undergoing staple processing in a stapling unit (not shown in the drawing), the shunting roller 100 rotates so as to receive the subsequent recording media, whereafter, when the staple processing is finished, the shunted recording media and the recording media output from the image forming device main body are fed to the stapling unit at the same time.
However, with the prior art described above, given the length, in the direction of transport, of the recording media that passes through the transport path 101a and the transport path 101b, it is necessary to provide a transport roller for transporting the recording media to the bottom of the shunting roller 100 (transport path side); and in the case of the prior art, a transport roller 103 is provided commonly on a mounting shaft for a branching pawl 104, as a result of which radial load and rotation are applied to this branching pawl 104, which results in malfunction.
Meanwhile, if the transport roller 103 is provided on a transport path 101c, downstream from a branching pawl 105, in the direction of transport, it is necessary to provide an additional separate transport roller on the shunting path 102, in the vicinity of the branching pawl 105. Furthermore, the prior art presents such problems as those wherein, when the recording media is transported to the stapling unit (not shown in the drawing), the transport roller 103 rotates in reverse, as a result of which, there is a risk of the edge of the recording media touching the transport roller 103 and jamming.
Thus, an object of the present invention is to provide a recording media processing device and an image forming device capable of smoothly switching the transport direction, with a first branching pawl and a second branching pawl, and having a transport roller provided in the direction of transport between the first and the second branching pawls so as to overlap therewith when seen from the side.